Speakers convert electrical signals to sound via the use of drivers. A conventional driver for a speaker assembly is shown in FIGS. 1 and 2. Some such common, traditional drivers 1 include a basket or frame 12 having a general cone shape, and the frame 12 supports a lightweight diaphragm 18. The diaphragm 18 is attached to the basket or frame 12 via a surround 20 along a wide edge 16 of the frame 12 and via a spider 22 along a narrow edge 14 of the frame 12. Attached to the diaphragm 18 is a wire voice coil 40 wound surrounding a pole piece 38 that sits at the center of a disc-shaped magnet 28 that is sandwiched between a front plate 24 and a rear plate 26.
The magnet 28 is usually polarized in the direction of the magnet's 28 thickness, e.g., with the north pole adjacent to a front face 30 of the magnet 28 and the south pole adjacent to a back face 32 of the magnet 28. This generates a magnetic flux that is dense in the gap between the top of the pole piece 38 and the front plate 24. The voice coil 40 is arranged to be located within this gap between the pole piece 38 and the metal front plate 24. An electrical signal is applied to the voice coil 40, which in turn makes the voice coil 40 an electromagnet and produces a magnetic field. The voice coil's 40 magnetic field interacts with the magnet 28 and metallic front plate 24 and metallic rear plate 26 so as to generate a mechanic force that causes the voice coil 40 to move forward or backwards, or, as the case may be, upwards or downwards, depending upon the signal sent to the voice coil 40. The physical vibrating motion of the voice coil 40 causes the diaphragm 18, to which the voice coil 40 is connected, to move or vibrate, which vibration produces audible sounds.
As shown in FIGS. 1 and 2, a conventional driver 1 further includes a dust cap 3 that covers the pole piece 38, which is, itself, an essentially-cylindrically-shaped metallic part. Further, these conventional drivers 1 are commonly generally thick, e.g., on the order of three-to-four inches in height from the wide outer edge of the frame 12 to the back of the rear plate 26, where such height defines the total thickness of the traditional driver 1. Accordingly, when installed within a structure, the single driver 1 occupies a fair amount of space within the structure and has a particular footprint. Acquiring the sound output of more than one traditional driver 1 generally requires the installation and visible footprint of more than one driver 1. Also, unless separate measures are taken to counteract the physical vibrations generated by the diaphragm 18 of the driver 1, the vibrations are apt to transfer to the structure, such as the container of baffle, in which the driver 1 is mounted, which transfer is undesirable, particularly when the structure is a wall within a household occupied by more than just the individual listening to the speaker assembly that includes the driver 1.